Automatic screw-cutting and turning lathe.



'J. GOULTER.

AUTOMATIC SGBEW CUTTING AND TURNING LATHE.

' APPLICATION FILED APR. 4, 1905.

908,960. Patented Jan. 5, 1909.

2 SHEETS-SHEET 1.

J. GOULTER.

AUTOMATIC SCREW CUTTING AND TURNING LATHE.

APPLICATION FILED APR.4,1905.'

908,960. I Patented Jan.5,19o9.

WITNESSES: NVENTOR JAMES COULTER, OF BRIDGFPORT, CONNECTlCUT.

auroiia'nc scanw-c'o'rrntc mums Lanna.

Specification of Letters Fatei t.

Ratented an. o

Application 11154 April 4, 1905. new no. can

To all whom it concern:

. Be it known that 1, JAMES CoUL'mR, a citizen of the United States, and a'residentof Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Automatic Screw Cutting and Turnin Lathes, of which the followin is a speci cation.

My inventionre ates to automatic screw cutting and turning lathes, and is an improvement on the patent granted to me Feb-. ruary 14th 1905 #7 82,220 and it consists, while running the lathe spindle and feed screw continuously in one direction, in utilizing the reversing-shaft for automatically disengaging the feed-nut from the feed or lead screw at the same time that the cutting-tools are withdrawn; and thus leave the carriage free to be instantly returned to .the starting point by means of a weight, and to automatically reengage the feed-nut with the,

feed-screw at the same time that the cutting- 'tools are reenga ed with the work at such starting point; t us greatly shortening the operation of cutting threads or turning work, and thereby materially cheapening the product over the present method of running the carriage back by means of the feedscrew. 7

To enable others to understand my invention, reference is had to the accompanying drawings in' which:

Figure 11s a rear elevation of the lathe:

Fig. 2-is a broken sectional view of the lathe, bed, and cross sectional view of the feed-screw and reversing-shaft throu 'h line a a of Fig. .1; also broken view of t e carriage showing the cams on the reversingshaft for operating the tool-holders:- Fi" 3is a cross sectional view of the fee 4 screw and reversing-shaft, and detail side elevation of the slide adapted to carry one of the tool-holders, and the feed-nut to en-' gage with the feed-screw: Fig. 4-,- is .a roken view of the feed-screw and upper plan view of its traveling support, and an upper plan view of the feed-nut: Fig. 5 is a brokenview of the reversing-shaft broken view of one of thetool-holder su ports showing its connection with one of t e cams on the reversing-shaft, and broken view of the sliding-bar that. operates the other tool-holder: Fig. 6- is an enlarged broken view of the head-stock and a crossv sectional view of the reversing-shaft through line b b of Fig. 1, showing the escapement mechanism with the reversing-shaft: F 7 is a broken view of the reversing-she and head-stock looking in the direction of arrow '0 of Fig. 6. Y

A brief description of the old features of the lathe. will assist very materially in understanding the improvements added there: to. These oldfeatures comprise the bed 1 on which is mounted the traveling carriage 2. 3 and 4 are slides mounted on the carriag'e carrying the tool-holders 5 and'6. 7

and 8 are the cutting-tools. 'Ifhe tool-holders 5 and 6 are moved on said slides to and from the work 9 by means of the shaft 10 having the right and left hand threaded ortions 10 and 10 operating in threaded oles of the lugs '11. and 12. This shaft is operated either by hand or automatically through the medium of the handles 13. As the means for operating this shaft are fully explained in my former patent, a detail description is unnecessary here.

14 is the reversing-shaft having the two cams 15 and 16, one to engage the uprights 17 of the sliding-bar 18, to which the toolholder slide 3 is secured by the screws 19, as shown at Fig. 2,'and the cam '16 to engage with the steel pieces 20 of the slide 4, shown more clearly at Fig. 5, so that, by means of these cams, the slides and tool holders are automatically moved to and from the work.

,ment of the shaft 14 is temporarily checked by the escapement mechanism comprising, see also Figs. 6 and 7, the collar 22 secured to said shaft, which collar has the lip 23 adapted to alternately engage with the stop 24, secured to the head-stock of the lathe, and the stop 25 also secured to said head-. stock.

26 and 27 are collars adjustably mounted on the reversing-shaft and they are adapted to be set to represent the travel of .the lathe carriage in either direction so that, .when feeding forward, the carriage will engage the collar 27 and move the reversing-shaft in the same direction, and thereby disengage the collar 22 from the stop 24, and, when so disengaged, the friction device will partially rotate said shaft to bring the lip 23 of said collar into engagement with the other stop 25. During this partial rotation of the re- -versing-shaft, the earns 15 and 16 will have I moved the slides 3 and 4, and also their toolover the pn holders in opposite direction to withdraw the cutting-tools from the work as shown at Fig. 1, and when the carriage, on its return, engages the collar 26, the tools are reengaged with the work.

In my former construction, the lathe spindle and feed-screw were reversed, but in my present construction the lathe spindle and feed-screw run continuously in one direction, and the carriage is automatically brought into en agement with the feed-screw and disengage therefrom in the manner presently to be explained. The lathe-spindle 28 carries the plnion 29 to mesh with the gear 30 on the reversing-shaft, and this gear, or an intermediate thereof, as the case may be, to mesh withthe pinion 31 on the feedscrew 32. The necessary motion is imparted to these parts through the medium of the cone pulleys 33 on the lathe-spindle.

34, Fig. 2, is a bracket secured to the underside of the lathe-carriage having the head portion 34 adapted to embrace andsupport the feed-screw 32. 35, see also Figs. 3 and 4, is another bracket secured to the underside ofthe slide 18, and 36 is a half nut secured to the lower end of the said bracket by the screw 37. This nut is adapted to be engaged with and disengaged-from the feed-screw as follows: 38, F ig. 1, is a chain attached to the lathe-carriage, and, running over the pulley 39, carries at its free end the weight 40. lrVhen, therefore, the forward movement of the carriage engages the collar 27 on the reversing-shaft and causes the slides 3 and 4 to move outward, as before mentioned, the feed-nut 36 will, of course, be carried back by the. slide 18 to disengage the carriage from the feed-screw; this will bring the carriage entirely under the control of the weight 40 so that, the moment the feed-nut is withdrawn from the feed-screw, the weight will instantly return the carriage, and, as soon as it strikes the collar 26 of'the reversing-shaft, the feed-nut and feed-screw are reengaged on the return movement of the slide 18. To prevent a jar or shock when the carriage is brought suddenly in contact with the collar 26, I provide an air cushion on the reversing-shaft, which cushion is represented by the cylinder 41. As the means for forming this air cushion are well known, it is not necessary to enter into a detail description of its construction.

In cutting left hand threads, the feedscrew is reversed in the usual manner, by means of intermediate gears, and the weight 40 is transferred to the chain 42, leadlng from the opposite side of the carriage an ley 43, and the weight'44 on this chain will be transferred to the chain 38. This latter weight is intended only to take up the slack in the chain not used by the heavy or carriage returning weight.

While I show frontand rear tool-posts in operation, it will be understood that there are times when only the front one is required, in which case, the rear one can be removed.

In my former construction, there were many more parts connected with the lathe than are required in the present and improved construction, and, too, it was very much slower in its operation. In order to return the carriage, both the lathe, spindle and feed-screw had to be reversed, and the carriage was returned entirely by the feedscrew. In my present construction, the lathe spindle, as before mentioned, and feedscrew run continuously in one direction so that, by throwing out the feed-nut at the same time that the cutting-tools are thrown out, and returning the carriage by means of a weight, I avoid the delay caused by running the carriage back by the slow working process of the feed-screwl.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an automatic machine of the char acter described, the combination with a traveling carriage, a tool-holder thereon, a shaft for actuating said} holder to and from the work, of a continuously running spindle and feed-screw, a reversing shaft, 2. feed-nut carried by the carriage and adapted for engagement and disengagement with the feed-screw, means connected with the reversing shaft for actuating said feed-nut, and a weight for returning said carriage when the feed-nut is out of engagement with the feed-screw, for the purpose set forth.

2. In an automatic machine of the character described, the combination with a traveling carriage, a tool-holder thereon, a shaft for actuating said holder to and from the work, of a continuously runnin spindle and a feed-screw, a reversing sha t, a feed-nut carried by the carriage and adapted for engagement and disengagement with'the feedscrw, means connected with the reversing shaft for actuating said feed-nut, for the purpose set forth.

Signed at Bridgeport, in the county of Fairfield and State of-Connecticut, this 2d day of Mar. A. D. 1905.

JAMES COULTER.

Witnesses:

FREDK. L. Ku'rscmm, J. W. RANGE. 

